Table 1.
Participant characteristicsa,b
| RA patients n=227 |
Controls n=300 |
P-valuec | |
|---|---|---|---|
| Age (years) | 64 (53, 71) | 46 (35, 55) | <0.0001 |
| Female sex | 153 (67) | 161 (54) | 0.001 |
| Body mass index (kg/m2) | 26 (23, 29) | 26 (23, 29) | 0.96 |
| Ever smoker | 150 (66) | 105 (35) | <0.001 |
| Resting heart rate (beats per minute) | 68 (62, 76) | 68 (63, 73) | 0.62 |
| Degree of morning stiffness (scale 0-10) | 4 (1, 6) | 1 (0, 2) | <0.0001 |
| Intensity of joint pain past 6 months (scale 0-10) | 4 (2, 6) | 0 (0, 2) | <0.0001 |
| Degree of pain in neck/back/hips (scale 0-10) | 4 (1, 7) | 2 (0, 4) | <0.0001 |
| Physical activity frequency | 0.009 | ||
| Less than once per week | 24 (11) | 19 (6) | |
| Once per week | 36 (16) | 28 (9) | |
| 2-3 times per week | 98 (43) | 130 (44) | |
| Almost every day | 68 (30) | 122 (41) | |
| Physical activity average intensityd | <0.001 | ||
| Take it easy | 76 (33) | 58 (19) | |
| Heavy breathing or sweat | 117 (52) | 211 (70) | |
| Near exhaustion | 7 (3) | 11 (4) | |
| Physical activity average durationd | 0.27 | ||
| Less than 15 minutes | 5 (2) | 3 (1) | |
| 15-29 minutes | 33 (15) | 56 (19) | |
| 30-60 minutes | 115 (51) | 168 (56) | |
| More than 60 minutes | 48 (21) | 53 (18) | |
| Fulfilled the EULAR aerobic physical activity recommendations | 63 (28) | 104 (35) | 0.11 |
| Estimated cardiorespiratory fitness (mL/kg/min) | |||
| Overall | 30.9 (±10.1) | 39.8 (±7.2) | <0.0001 |
| Women | 27.8 (±7.8) | 36.3 (±5.8) | <0.0001 |
| Men | 37.2 (±11.5) | 44.0 (±6.5) | <0.0001 |
| Cohen’s perceived stress scale (scale 0-40) | 14 (9, 18) | 10 (7, 14) | <0.0001 |
| HADS-D (scale 0-21) | 3 (1, 5) | 1 (0, 3) | <0.0001 |
| RA specific information | |||
| Age when diagnosed (years) | 48 (±15) | ||
| Disease duration (years) | 11 (5, 20) | ||
| Positive for anti-citrullinated protein antibody | 167 (74) | ||
| Positive for rheumatoid factor | 159 (70) | ||
| Patient global assessment (mm, scale 0-100) | 29 (14, 48) | ||
| mHAQ (scale 0.00-3.00) | 0.25 (0.00, 0.63) | ||
| Degree of joint tenderness or swelling (scale 0-10) | 2 (1, 5) | ||
| Medication - current use | |||
| Conventional DMARDs | 186 (82) | ||
| Biological DMARDs | 116 (51) | ||
| Glucocorticoids | 51 (22) | ||
| Comorbidities | |||
| Hypertension | 68 (30) | ||
| Respiratory diseasee | 43 (19) | ||
| Cardiovascular diseasef | 42 (19) | ||
| Cancer | 22 (10) | ||
| Diabetes | 14 (6) |
aPresented as number with percentage, median with 25th and 75th percentile, or mean with standard deviation as appropriate
bAbbreviations: DMARDs disease-modifying antirheumatic drugs, EULAR European Alliance of Associations for Rheumatology, HADS-D Hospital Anxiety and Depression Scale’s Depression Score, mHAQ modified Health Assessment Questionnaire, RA rheumatoid arthritis
cChi-square test, Mann Whitney U-test or t-test as appropriate
dOnly participants performing physical activity at least weekly were asked to report intensity and duration
eRespiratory disease: chronic obstructive pulmonary disease, chronic restrictive pulmonary disease, or asthma
fCardiovascular disease: myocardial infarction, angina, heart failure, arrhythmia, or stroke